Conventionally, in order to intuitively and quantitatively evaluate a state of a cartilage in an articular cavity, various types of system that apply an ultrasonic wave to the cartilage and generate analysis data based on a reflection echo.
For example, JP2002-345821(A) discloses an ultrasonic analyzing system, in which an endoscope provided with an ultrasonic transceiving body at a tip end thereof is inserted in an arthrosis, and an echo of a pulse signal which is transmitted from the ultrasonic transceiving body is acquired. Then, a wavelet transformation of the echo signal is carried out to display a cartilage thickness result which is calculated based on a cartilage surface echo level, a cartilage surface echo pulse width, and an assumed sound speed.
However, the above conventional method disclosed in JP2002-345821(A) requires a surgical operation, such as inserting the endoscope (i.e., the ultrasonic transceiving body) into a patient's body. For this reason, the patient tends to feel burdensome to have a doctor examine the cartilage state when the patient feels his/her knee being in a bad condition, which typically is an initial state of cartilage degeneration or osteoarthritis, for example.